AbstractAcrylate rubber molecules contain sterically hindered and highly polar ester groups, which can generate a large amount of internal friction energy under external alternating stress and ...exhibit high internal friction for energy dissipation. Based on previous studies on the formulation of acrylate viscoelastic materials, the optimal formulation was prepared and made into acrylate viscoelastic dampers and the mechanical properties of the corresponding damper specimens were tested. The acrylate viscoelastic dampers at different ambient temperatures, excitation frequencies, and displacement amplitudes were systematically investigated. The experimental results indicate an excellent damping capacity of the acrylate viscoelastic dampers, where the dynamic properties are affected by the ambient temperature and excitation frequency, and the single-loop energy dissipation capacity is significantly affected by the displacement amplitude. To accurately represent the effects of the temperature, frequency, and amplitude on the dynamic properties of the damper, a modified fractional-derivative equivalent model is introduced, where the internal variable theory and temperature-frequency equivalent principle are introduced to reflect the amplitude effect and temperature effect, respectively. Finally, the results calculated by the proposed model were compared with the experimental data, which verified the correctness of the mathematical model.
As one of the most promising cathode candidates for room‐temperature sodium‐ion batteries (SIBs), P2‐type layered oxides face the challenge of simultaneously realizing high‐rate performance while ...achieving long cycle life. Here, a stable Na2/3Ni1/6Mn2/3Cu1/9Mg1/18O2 cathode material is proposed that consists of multiple‐layer oriented stacking nanoflakes, in which the nickel sites are partially substituted by copper and magnesium, a characteristic of the material that is confirmed by multiscale scanning transmission electron microscopy and electron energy loss spectroscopy techniques. Owing to the optimal morphology structure modulation and chemical element substitution strategy, the electrode displays remarkable rate performance (73% capacity retention at 30C compared to 0.5C) and outstanding cycling stability in Na half‐cell system couple with unprecedented full battery performance. The underlying thermal stability, phase stability, and Na+ storage mechanisms are clearly elucidated through the systematical characterizations of electrochemical behaviors, in situ X‐ray diffraction at different temperatures, and operando X‐ray diffraction upon Na+ deintercalation/intercalation. Surprisingly, a quasi‐solid‐solution reaction is switched to an absolute solid‐solution reaction and a capacitive Na+ storage mechanism is demonstrated via quantitative electrochemical kinetics calculation during charge/discharge process. Such a simple and effective strategy might reveal a new avenue into the rational design of excellent rate capability and long cycle stability cathode materials for practical SIBs.
A stable copper and magnesium cosubstituted Na2/3Ni1/6Mn2/3Cu1/9Mg1/18O2 cathode material consisting of multiple‐layer oriented stacking nanoflakes is reported. An optimal structure design and a chemical element substitution strategy are demonstrated to greatly improve Na+ transport kinetics and structural stability of P2‐type cathode material, resulting in high‐rate and long cycle life for a sodium‐ion battery.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Polar materials, with intrinsic polarization effects, present significant potential for photo(electro)catalysis. However, the available natural polar materials in this field are quite scarce, due to ...the requisite structural non‐centrosymmetry. Defect engineering emerges as a promising avenue for tuning material symmetry, yet achieving the transition from centrosymmetric to non‐centrosymmetric structures and optimizing associated polarization effects remains challenging. This study demonstrates symmetry breaking in centrosymmetric 3R‐delafossite AgFeO2 through ordered oxygen defects introduction, yielding substantial macroscopic polarization. The transition is achieved via annealing post‐treatment of co‐precipitation‐hydrothermal AgFeO2 samples, with precision in oxygen defects control by tailoring annealing conditions. Experimental characterizations reveal ordered interstitial oxygen and disordered oxygen vacancies. Density functional theory calculations indicate a higher propensity for the formation of disordered oxygen vacancies compared to ordered ones, while ordered interstitial oxygen is more easily formed than its disordered counterpart. Resultant macroscopic polarization enhances photoelectrochemical performance, with photocurrent density increasing from 0.79 to 2.95 µA cm−2. Coupling macroscopic and spin polarization via external electric and magnetic fields further enhances photocurrent density (≈18.44 µA cm−2). These findings provide reference cases and strategies for applying polarization effects in photo(electro)catalytic technology.
Oxygen defect engineering is employed to break symmetry and induce macroscopic polarization in AgFeO2 photocathodes, significantly boosting PEC performance. Ordered interstitial oxygen incorporation results in a substantial photocurrent density enhancement, and the application of external electric and magnetic fields further amplifies this effect, demonstrating a synergistic strategy and multi‐physics field coupling for further improving solar‐to‐hydrogen conversion efficiency.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Natural antioxidants are widely distributed in food and medicinal plants. These natural antioxidants, especially polyphenols and carotenoids, exhibit a wide range of biological effects, including ...anti-inflammatory, anti-aging, anti-atherosclerosis and anticancer. The effective extraction and proper assessment of antioxidants from food and medicinal plants are crucial to explore the potential antioxidant sources and promote the application in functional foods, pharmaceuticals and food additives. The present paper provides comprehensive information on the green extraction technologies of natural antioxidants, assessment of antioxidant activity at chemical and cellular based levels and their main resources from food and medicinal plants.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Solid-liquid interface is a key concept of many research fields, enabling numerous physical phenomena and practical applications. For example, electrode-electrolyte interfaces with electric double ...layers have been widely used in energy storage and regulating physical properties of functional materials. Creating a specific interface allows emergent functionalities and effects. Here, we show the artificial control of ferroelectric-liquid interfacial structures to switch polarization states reversibly in a van der Waals layered ferroelectric CuInP
S
(CIPS). We discover that upward and downward polarization states can be induced by spontaneous physical adsorption of dodecylbenzenesulphonate anions and N,N-diethyl-N-methyl-N-(2-methoxyethyl)-ammonium cations, respectively, at the ferroelectric-liquid interface. This distinctive approach circumvents the structural damage of CIPS caused by Cu-ion conductivity during electrical switching process. Moreover, the polarized state features super-long retention time (>1 year). The interplay between ferroelectric dipoles and adsorbed organic ions has been studied systematically by comparative experiments and first-principles calculations. Such ion adsorption-induced reversible polarization switching in a van der Waals ferroelectric enriches the functionalities of solid-liquid interfaces, offering opportunities for liquid-controlled two-dimensional ferroelectric-based devices.
The genus
is a member of the Celastraceae family, of which several species have long been used in traditional medicine. Between 1976 and 2021, nearly 270 new compounds have been isolated and ...elucidated from the genus
. Among these, maytansine and its homologues are extremely rare in nature. Owing to its unique skeleton and remarkable bioactivities, maytansine has attracted many synthetic endeavors in order to construct its core structure. In this paper, the current status of the past 45 years of research on
, with respect to its chemical and biological activities are discussed. The chemical research includes its structural classification into triterpenoids, sesquiterpenes and alkaloids, along with several chemical synthesis methods of maytansine or maytansine fragments. The biological activity research includes activities, such as anti-tumor, anti-bacterial and anti-inflammatory activities, as well as HIV inhibition, which can provide a theoretical basis for the better development and utilization of the
.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Since the creation of first man-made plastic, the global production and consumption of plastics have been continuously increasing. However, because plastic materials are durable and very slow to ...degrade, they become waste with high staying power. The over-consumption, disposal, and littering of plastics result in pollution, thus causing serious environmental consequences. To date, only a fraction of waste plastics is reused and recycled. In fact, recycling plastics remains a great challenge because of technical challenges and relatively insufficient profits, especially in mixed plastics. This review focuses on an environmentally friendly and potentially profitable method for plastics separation and recovery and solvents extraction. It includes the dissolution/reprecipitation method and supercritical fluid extraction, which produce high-quality recovered plastics comparable to virgin materials. These methods are summarized and discussed taking mass-produced plastics (PS, PC, Polyolefins, PET, ABS, and PVC) as examples. To exploit the method, the quality and efficiency of solvent extraction are elaborated. By eliminating these technical challenges, the solvent extraction method is becoming more promising and sustainable for plastic issues and polymer markets.
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•Solvent extraction is a promising method to separate waste mixed plastics.•The method is potentially applied for recycling mass-produced plastics.•The method is environmentally benign and is potentially profitable.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Cyclic peptides can bind to protein targets with high affinities and selectivities, which makes them an attractive modality for the development of research reagents and therapeutics. Additional ...properties, including low inherent toxicity, efficient chemical synthesis, and facile modification with labels or immobilization reagents, increase their attractiveness. Cyclic peptide ligands against a wide range of protein targets have been isolated from natural sources such as bacteria, fungi, plants, and animals. Many of them are currently used as research tools, and several have found application as therapeutics, such as the peptide hormones oxytocin and vasopressin and the antibiotics vancomycin and daptomycin, proving the utility of cyclic peptides in research and medicine. With the advent of phage display and other in vitro evolution techniques, it has become possible to generate cyclic peptide binders to diverse protein targets for which no natural peptides have been discovered. A highly robust and widely applied approach is based on the cyclization of peptides displayed on phage via a disulfide bridge. Disulfide-cyclized peptide ligands to more than a hundred different proteins have been reported in the literature. Technology advances achieved over the last three decades, including methods for generating larger phage display libraries, improved phage panning protocols, new cyclic peptide formats, and high-throughput sequencing, have enabled the generation of cyclic peptides with ever better binding affinities to more challenging targets. A relatively new cyclic peptide format developed using phage display involves bicyclic peptides. These molecules consist of two macrocyclic peptide rings cyclized through a chemical linker. Compared to monocyclic peptides of comparable molecular mass, bicyclic peptides are more constrained in their conformation. As a result, they can bind to their targets with a higher affinity and are more resistant to proteolytic degradation. Phage-encoded bicyclic peptides are generated by chemically cyclizing random peptide libraries on phage. Binders are identified by conventional phage panning and DNA sequencing. Next-generation sequencing and new sequence alignment tools have enabled the rapid identification of bicyclic peptides. Bicyclic peptide ligands were developed against a range of diverse target classes including enzymes, receptors, and cytokines. Most ligands bind with nanomolar affinities, with some reaching the picomolar range. To date, several bicyclic peptides have been positively evaluated in preclinical studies, and the first clinical tests are in sight. While bicyclic peptide phage display was developed with therapeutic applications in mind, these peptides are increasingly used as research tools for target evaluation or as basic research probes as well. Given the efficient development method, the ease of synthesis and handling, and the favorable binding and biophysical properties, bicyclic peptides are being developed against more and more targets, ever increasing their potential applications in research and medicine.
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IJS, KILJ, NUK, PNG, UL, UM
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•Multifunctional elastomer foams were achieved by thermos-expandable microspheres.•Piezoresistivity of foams was improved by adding thermos-expandable microspheres.•The foams showed ...distinguishing signal response, reliability and stability.•The unfoamed composites showed NTC first and then PTC, finally NTC again.•Microwave shielding was greatly improved by adding thermos-expandable microspheres.
In this work, the multifunctional elastomer foam with robust mechanical properties, highly piezoresistive sensitivity, special temperature-sensitive characteristic and excellent EMI shielding property was successfully fabricated by directly introducing thermo-expandable microspheres (EM) into polydimethylsiloxane/multi-walled carbon nanotube (PDMS/CNT). It was found that the addition of EM enhanced the piezoresistivity, integrating the properties of quick response (60 ms), excellent reliability and extraordinary stability. For example, the value of I/I0 in the PDMS/EM/CNT composites with 30 wt% EM and 1.0 wt% CNT achieved 1800% enhancement compared to the composites without EM. Besides, the self-reinforced PDMS/EM/CNT elastomer with unique softening behavior showed great potential in strain alerting device. Moreover, the special temperature-sensitive sensing in the unfoamed PDMS/EM/CNT sample was studied in detail, exhibiting the NTC effect first, and then PTC effect, finally NTC again. Furthermore, the EMI shielding performance got incredible improvement due to the introduction of multiple interfaces and the enhancement of conductivity. For example, by incorporating 10, 30 and 50 vol% EM into the PDMS/CNT composites, the improved EMI SE of ~32, ~36 and ~43 dB were gained, respectively.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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